Coffee Joulies use phase change material to make your cup’s temp just right

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People who drink coffee know how much it sucks when you grab a cup from your local coffee shop, take sip, and recoil from the burning hot liquid you need so badly to start your day. If only there was a way to cool your coffee down quickly, without sticking ice cubes in it, or leaving the lid off for 5 minutes before you can take another sip… Fortunately, two guys named Dave have created a solution to this common problem with a product called Coffee Joulies.

Dave Petrillo and Dave Jackson spent the past nine months working from opposite ends of the country to develop Joulies with the intent of creating the “perfect coffee drinking experience.” The Joulies absorb extra thermal energy in your coffee when it’s too hot, and cools it down to a drinkable temperature three times faster than if you sat and waited. Joulies also releases that stored energy back into your coffee, which keeps it at the right temperature for twice as long.

For those of you thinking this process sounds very similar to that of phase change materials, you’d be right. The polished stainless steel beans hold this high-tech stuff inside of them, which is how the magic beans work. The PCM is a solid, but it melts like wax when heated and turns to a liquid. The PCM is designed to melt at 140 degrees. Most coffee is brewed at 200 degrees. So, as the material melts it absorbs the heat of the coffee, stores it, and brings the coffee’s temperature down to the right temp. Then, it slowly releases this stored energy back into the coffee as the material starts to solidify again, and keeps your coffee warm twice as long.

Of course, the better insulated your cup is, the better the Joulies will work. In a ceramic mug, Joulies will keep your coffee at the right temperature range for only a few minutes longer than usual. This is because mugs are poor insulators and are designed to keep your hand from being burned. Putting a lid on your coffee will make a difference, since the less heat that’s lost to the environment, the more is stored in the Joulies.

Though the Joulies are marketed towards hot beverages like coffee and tea, we see no reason as to why it couldn’t work reversely, and keep cool beverages cool for a longer period of time.

Each Joulie is made to work with 5 ounces of volume and displace about 1.5 tablespoons per bean. They take up about 15 percent of the volume of your cup or thermos, which is about the same amount you’d use for cream. Since they’re made using the same materials and a very similar process as table knives, they’re supposed to last a lifetime.

You can’t rush out to buy these just yet. The two Daves are looking for some support via Kickstarter, but you can pre-order a set of five Coffee Jouilies packaged in a reusable carrying pouch for 20 percent off the $50 retail price. There are additional packages at higher levels to help the product get off the ground, which you can see at the Kickstarter page.